<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
    <style type="text/css">
      html { height: 100% }
      body { height: 100%; margin: 0; padding: 0;}
      #map_canvas { height: 100% }
    </style>
    <script type="text/javascript"
      src="https://maps.googleapis.com/maps/api/js?key=AIzaSyAIexWsFhKlPnaANqwxwpfWdm3s6zeAklg&sensor=false">
    </script>
    <script type="text/javascript">
	  var map,line;
      function initialize() {
        var mapOptions = {
          center: new google.maps.LatLng(0, 0),
          zoom: 1,
          mapTypeId: google.maps.MapTypeId.ROADMAP,
		  streetViewControl: false
        };
        map = new google.maps.Map(document.getElementById("map_canvas"),mapOptions);
		var lineOptions = {
		  map:map,
		  strokeColor:"#33ccff",
		  strokeWeight:7
		}
		line = new google.maps.Polyline(lineOptions);
      }
	  
	  function setCentre(lat,lon){
		map.panTo(new google.maps.LatLng(lat,lon));
	  }
	  
	  function setZoom(zoom){
	  	map.setZoom(zoom);
	  }
	  
	  function addPoint(lat,lon){
		line.getPath().push(new google.maps.LatLng(lat,lon));
	  }
    </script>
  </head>
  <body onload="initialize()">
    <div id="map_canvas" style="width:100%; height:100%"></div>
  </body>
</html>